This does use KaTeX for rendering the TeX:
> Math support is the core functionality of mdmath. Inline math $r = \sqrt{x^2 + y^2}$ and display math expressions $$e^{ix}=\cos x + i\sin x$$ are supported, due to markdown-it extension markdown-it-texmath [8] and the fast math renderer KaTeX [9].
> [8] markdown-it-texmath, (https://github.com/goessner/markdown-it-texmath).
> [9] KaTeX, (https://katex.org/)
This does use KaTeX for rendering the TeX:
> Math support is the core functionality of mdmath. Inline math $r = \sqrt{x^2 + y^2}$ and display math expressions $$e^{ix}=\cos x + i\sin x$$ are supported, due to markdown-it extension markdown-it-texmath [8] and the fast math renderer KaTeX [9].
> [8] markdown-it-texmath, (https://github.com/goessner/markdown-it-texmath).
> [9] KaTeX, (https://katex.org/)